Human waste contains an unparalleled amount o health-related information. In particular, urine is routinely analyzed by healthcare professionals to obtain information regarding an individual's disease state, hormonal balance, nutritional status, pharmaceutical use, metabolic activity, microbial balance, risks of future health complications and other clinical points of interest. Conventionally, this information is obtained following sample submission to a laboratory; however, laboratory analysis typically only provides single-point data and is often a lengthy and awkward process for patients. Since human health is not an isolated event, the health information provided by the current testing methodology offers mere glimpses into an individual's health status. Ideally, key health measures would be assessed on an ongoing basis; however, the cost and inconvenience of laboratory analysis make regular testing prohibitive for the majority of people. In contrast, an on-site, in situ urine collection and analysis unit capable of delivering accurate, continuous and minimally invasive health testing would offer unprecedented longitudinal health-related information to individuals and healthcare professionals. Such in situ sample collection and analysis is most conveniently achieved at the typical site of urine excretion: the toilet, urinal, or pot.
Urine collection methods designed for on-site urine analysis have been described previously. For example, U.S. Pat. No. 5,073,500 (hereafter referred to as reference 1, the entire disclosure of which is incorporated herein by this reference) describes a toilet apparatus which measures the concentrations of urinary components based on the specific wavelength-absorbing characteristics of a urine sample following passage through a liquid chromatograph. Urine is collected in a large funnel located at the front of the toilet bowl that channels samples into an automated liquid chromatography system, where it is separated into sample aliquots by gas injection, combined with a urinary component-specific reagent, forced through a liquid chromatograph and then exposed to a component-specific wavelength of light. The system is neither convenient nor practical for unassisted personal use.
A more practical approach to analysis is described U.S. Pat. No. 5,772,406 (hereafter referred to as reference 2, the entire disclosure of which is incorporated herein by reference), which describes a toilet stool-based spectroscopic system that analyzes uric component concentrations by measuring urine sample absorbance of select wavelengths of visible or near-infrared light. In this system, a urine collecting basin is located in the front of a toilet bowl. Urine that enters the basin passes through a screen into a tube, where it is held back by a valve. When the system is ready process urine, the valve opens and urine flows down the tube through a spectral analysis cell to a closed secondary valve. A liquid sensor determines whether sufficient urine has been captured to fill the spectral analysis cell. If so, analysis is conducted. Following the analysis, the secondary valve is opened and the urine is evacuated to the sewage system. The system then undergoes a flush cycle which is monitored by a sensor to insure that the urine collecting part and the spectral analysis cell are sufficiently clean to assure valid analytical results. This is accomplished using a washing solution that is discharged front a nozzle located opposite to the urine collecting basin. Once the spectral analysis cell is sufficiently clean, a cell blank measurement of the empty cell or of a water-filled cell is taken to establish a clean reference for the next sample.
Other creative methods employed for sample capture and analysis include U.S. Pat. No. 5,730,149 (hereafter referred to as reference 3, the entire disclosure of which is incorporated herein by reference), which describes an extensible, mechanically operated collection spoon. Following extension of the collection device, urine is captured mid-air and is forwarded via a flexible tube through the swing arm and spindle to the urinalysis device, where reagents are added to the sample for component quantification. U.S. Pat. No. 7,812,312 (hereafter referred to as reference 4, the entire disclosure of which is incorporated herein by reference) describes a system for analysis of aqueous systems using, attenuated total reflectance (ATR) crystals. In a toilet embodiment of the invention, the ATR body is preferentially designed as a flow-through cell with a reversibly closeable inlet and outlet incorporated into a separate sampling line branching from the toilet drain pipe.
Perhaps the most feasible in-toilet urine collection approach is outlined in U.S. Pat. No. 5,815,260 (hereafter referred to as reference 6, the entire disclosure of which is incorporated herein by reference), which describes a toilet stool-based analytical system that measures the concentrations of erogenous components using Raman spectroscopy. Urine is collected in a frontal basin which is connected to a light-emitting fiber optic cable and a light-receiving fiber. The light-emitting cable transmits light from a laser source across the basin and through the sample to the light-receiving cable which conducts the resultant light to a Raman spectrometer. Following spectral analysis, the basin is cleared by flush water and drained through a scupper to prepare the basin for a new collection and sampling procedure.
Unfortunately, previous attempts to facilitate automated urine specimen collection, preparation and analysis are hindered by mechanical complexity and difficulties in creating a spectral sampling pathlength of appropriate thickness that is also amenable to rapid sample evacuation and easy cleaning. For example, when sampling a liquid such as urine which is predominantly comprised of water with near-infrared spectroscopy, a transmission sample pathlength of 1 mm is necessary to obtain useitil results. While urine will flow through a gap of this size, the rate of flow is significantly hindered, and passage of a typical 300-800 mL sample of urine through such a space is unacceptably slow. Furthermore, expulsion of fecal matter into the collection unit represents a significant obstacle for quality analysis, especially if the fecal matter becomes lodged inside a collection tube with a 1 mm sampling area. In overcoming these obstacles, it is an object of the present invention to provide an automated urine specimen collection device capable of channeling urine through a spectral analysis site with a pathlength appropriate to the demands of the chosen spectrometer without significantly impinging the overall flow of urine or subsequent flush cycle. Additionally, the unit will be able to maintain a clean environment suitable to high quality spectral analysis. In so doing, the present invention allows for elegant in situ urine sampling and analysis.